docs: add Holopin badge guide for maintainers

[DarshanCode2005]

Closes https://github.com/asyncapi/community/issues/2041

Description

Adds comprehensive documentation for maintainers on how to set up and use Holopin digital badges to recognize contributors in their repositories.

Changes

• Created docs/040-guides/holopin-badge-workflow.md with:
  • Prerequisites (Holopin account setup, organization membership, GitHub linking)
  • Step-by-step setup instructions for holopin.yml configuration
  • Complete list of available badge types and their aliases
  • Usage guide for issuing badges via @holopin-bot
  • Troubleshooting section and support contacts
  • Links to official Holopin documentation

References

• Based on AsyncAPI's existing holopin.yml configuration
• References Holopin GitHub integration docs: https://docs.holopin.io/integrations/github
• Contact information for @thulieblack and @derberg for organization access

Related

Addresses the need for maintainer documentation on Holopin badge workflows as discussed in the community.

Summary by CodeRabbit

• Documentation
  • Added a comprehensive Holopin badge guide covering prerequisites, setup, how repository configuration is replicated, available badge types, issuing badges via comments, bot verification flow, and how badges appear on profiles.
  • Included troubleshooting, guidance for obtaining new badge designs, and contact resources; updated the docs index to list this workflow under Infrastructure and Operations.

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